I'm not sure, but I don't think we can call it 'fast mummies' if we need to gather 12
in a duo deck... and if we want to add
to eat anything with those scarabs then it would be even slower.
Adding
and anubises instead would allow us to protect pharaohs from rewinding, but would also make a very slow deck with little control.
It's not a big advantage if it rewinds a single creature each turn if you can only play it later when opponent already has a number of creatures on the field, and you have to worry about your own creatures too. Using it in mono-time would require you to use cheap creatures (deja vu probably would be best) but without buffs it would be very vulnerable to shields and RoF/plague/thunderstorm.
So basically in mono it's not a big advantage, in duo it's slow. The best use for it I can think of is to use it in conjunction with eternity in late game to rewind 2 or more creatures each turn without having to use flying eternities, but then you would only use it when you already have a lot of creatures in play and enough pillars to play them back after they are rewound.
I wonder if you could make any good creatureless decks with it. Maybe a
with only immaterial creatures could make a use of these.
At least that's what I think. I'm not saying it's underpowered, but it simply does not seem to have many advantages or uses that would actually help you win.